(1) Field of the Invention
This invention relates to the control of pests, such as insect pests, and is especially, but not exclusively, related to the control of flying or crawling insect pests.
(2) Description of the Related Art
It has been found that the use of pesticides, pheromones and other pest behaviour modifying agents can lead to many undesirable consequences. For example, the use of pesticide sprays in agricultural and domestic environments has been shown to lead to the development of pesticide resistance in the insect pest species. Such use has also been demonstrated to cause the killing of non-target animals, including beneficial species. Moreover, toxic residues therefrom accumulate in the environment which, subsequently, can be incorporated in the food chain and have consequential harmful effects on animal and human health. Therefore, it is desirable to target the pest species effectively and to minimise the amounts of pesticide which find their way into the environment and/or on to non-target organisms.
International Patent Application No. PCT/GB93/01442 (Publication No. WO 94/00980) discloses a method of accurately targeting pest species, including a method of luring one sex of an insect pest species to a bait using the sexual pheromone of that pest, usually in the form of a volatile attractant, contaminating the attracted insect with electrostatically charged powder or other particulate material formulated with a suitable slow-acting killing agent or behaviour-modifying chemical, and allowing the insect to contaminate the opposite sex of the same species during mating attempts. For this method to operate without harmful consequences, it is desirable that as much powder or other particulate material as possible attaches to the target species and is not lost into the environment where it can affect other organisms.
In many instances, it is desirable to distribute insect traps or baits from the air in order to cover large areas of crop effectively. This is especially suitable when it is desired to control pests of forest trees or pests of large-scale horticulture, or when it is desired to eradicate a pest species in an isolated zone, such as an island. However, when traps or baits in containers are dropped from the air, they lose some of their contents in the fall or by shaking as they land. In many cases it is desirable that the devices anchor in the trees with the openings in a particular orientation. More powder will be lost, and the distribution of the odorous attractant by air currents will be impeded, if the final location of the devices is incorrect.